Re: barrel programs...can I buy and age my own bar

> Does it make sense to increase the proof with high proof GNS? Maybe.
> The higher proof spirit will be more effective as a solvent for dissolving
> barrel "goodies,"

Well, that much is true, but it's not the whole story!
The hydrolysis of hemicellulose and other things in wood is accelerated by
increasing water content, so if your proof is really high, then you have
the ability to solubilize the goodies, you're just not producing them!

Piggott's book mentions a bourbon study showing that production
of color, volatile acids, and tannins all decrease as you increase
the proof at which you age.

So it's a trade-off. I think roughly 60% (120 proof) comes out to
be fairly optimal all things considered... but it really depends
on what you're after! If you're starting with pre-aged bourbon and
you just want mellowing, not extra sweetness and tannins, then higher
proof might be your friend.

Oh, and while I'm at it: smaller casks will give you more loss per year
than large casks. So the 5% figure might not hold. I have some numbers
somewhere comparing cask volume to percentage loss in Scotland... you
can triple your annual losses by using smaller casks. And by "smaller",
they mean the ~250 L (60 - 80 gallon) hogsheads (vs. the butts that
hold twice as much).

Prepare to pay the angels a fair bit if you're using ~10 gallon casks!

Re: barrel programs...can I buy and age my own bar

> Worried about it aging "too fast"? How fast is "too fast" and why is "fast"
> "too fast," as in something negative? Wouldn't you want to get some
> identifiable changes as quickly as possible? I can't see any benefit in
> retarding the aging.

What if it gets really woody really fast, but still has the "hot" flavor
of younger whiskey? Aging is many many things all going on at once...
ethanolysis, hydrolysis, dissolution, oxidation... lots of things are
interacting in complex ways.

> Remember, though, that it's the cycle of heating and cooling that
> changes the spirit. Getting it hot and keeping it hot doesn't get
> you anywhere.

Perhaps you've never had rum?

Getting it hot and keeping it hot will definitely give you lots of
aging! The annual cycle of heating and cooling gives subtle effects that
are only marginally different than, say, 4 straight years of steady
summer temperature followed by 4 straight years of winter temperature.

Not to be rude, but "Getting it hot and keeping it hot doesn't get you
anywhere" is just plain 100% false. Dunno how else to put it!

Re: barrel programs...can I buy and age my own bar

I hate to ask but which one is it; in this post you say that the proof goes up, and in the previous you say it goes down.

Also does Yoahizawa's study say whether these are the new oak barrels that are used in bourbon or the used barrels used for scotch. In my experience, porous substances tend to "clog" as more fluids flow through them. While I'm not sure what this would do to the permeability, it seems that since it makes no difference as to the size of the molecule, the used barrel might allow the different molecules to pass at rates other than what a new barrel would.

Also wouldn't those fluids flow differently based on the diffence between the sides of the "membrane". In a humid environment, water would flow slower, while alcohol would flow at the same rate (this is assuming a normal Earth environment containing very little alcohol vapors in the air-at least proportionate to that in the barrel).

One last thing I wonder about: the rate of evaporation of water compared to alcohol based on temp. It seems that alcohol, based on its lower freezing point, would continue to evaporate at an accelerated rate compared to water at the lower temps in Scotland.

I don't know the answers to any of these, just asking. I basing my thoughts on my own experiences. If you know the answers, please let me know.

Re: barrel programs...can I buy and age my own bar

> I hate to ask but which one is it; in this post you say that the proof
> goes up, and in the previous you say it goes down.

Oops! Sorry about that. I went ahead and edited my post... proof goes
down over time in Scotland, i.e. the ethanol leaves the barrel faster
than the water.

> In my experience, porous substances tend to "clog" as more fluids flow
> through them. While I'm not sure what this would do to the permeability,
> it seems that since it makes no difference as to the size of the molecule,
> the used barrel might allow the different molecules to pass at rates other
> than what a new barrel would.

It's entirely possible that the apparent porousity of the barrel changes over
time... luthiers can tell you that wood, even just sitting there in open air,
will lose weight over time. I can imagine that exposure to whiskey changes
the structure of the wood in interesting ways. I vaguely seem to recall that
the rate of loss and the rate of aging isn't enitrely constant, but does
change in small ways over the time that the whiskey is in the barrel. It's
more of a subtle thing, though, and I can't remember off hand whether it
speeds up or slows down over time. I would guess that the wood would tend
to open up and become more porous, since parts of the barrel are literally
decomposing and dissolving.

Also, recall whiskey that is in it's third year of aging is sitting in a
"used" barrel (it's been used for two years by the whiskey that's sitting in
it)... so even a new barrel is a used barrel.

> Also wouldn't those fluids flow differently based on the diffence between the
> sides of the "membrane". In a humid environment, water would flow slower,
> while alcohol would flow at the same rate (this is assuming a normal Earth
> environment containing very little alcohol vapors in the air-at least
> proportionate to that in the barrel).

Exactly! You've summarized nicely what they like to call Fick's First Law
of Diffusion: J = -D dc/dx. It's the best way to explain the Scotland vs.
America effect.

> One last thing I wonder about: the rate of evaporation of water compared to
> alcohol based on temp. It seems that alcohol, based on its lower freezing
> point, would continue to evaporate at an accelerated rate compared to water
> at the lower temps in Scotland.

You're right. (The term you're looking for is "vapor pressure".) It makes
for a very complex scenario indeed! I think you've hit most of the major
points with respect to aging. The only other thing worth mentioning is that
oxygen is continually diffusing into the barrel, so that the contents are
slowly oxidizing over time.

A lot of the questions about the microstructure of wood and how it relates
to permeability and how it changes over time really are a mystery... most of
the distilleries, wineries, etc. just know what seems to work for them.
They're still very interesting questions, though!

There are a lot of variables with temperature, humidity, temperature changes
over time, species of oak, tightness of grain in the oak, proof of the whiskey
inside... I have a feeling that no one has explored all of these, they just
find what works for them and stick with it. Even sticking to what would seem
like the same formula, there's still variation in taste between two
seemingly identical barrels that sit right next to each other in the warehouse!

For those of you who are a little shy when it comes to buying and filling
and storing a barrel, there is a smaller way to participate... although
it's not quite the same, and some would call it "cheating". Wineries often
put oak chips or sticks into the barrels to add more wood to the aging process.
I've seen quite a few reports of home distillers aging their whiskey in
glass bottles with such oak chips. It's not barrel aging, but it definitely
is wood aging!

Re: barrel programs...can I buy and age my own bar

"The annual cycle of heating and cooling gives subtle effects that are only marginally different than, say, 4 straight years of steady summer temperature followed by 4 straight years of winter temperature."

Tim, if this was true, why do distillers (some of them) make such a big thing about artificial cycling? Doesn't the practice result in red layer sugars entering the spirit faster than if natural seasonal variations (much less a constant multi-year temperature) occur? You refer to rum, but rum isn't really sweet and when it is, I suspect the sweet comes from added caramel or sugar, not lignin and other wood sugars.

Re: barrel programs...can I buy and age my own bar

For those of you who are a little shy when it comes to buying and filling
and storing a barrel, there is a smaller way to participate... although
it's not quite the same, and some would call it "cheating". Wineries often
put oak chips or sticks into the barrels to add more wood to the aging process.
I've seen quite a few reports of home distillers aging their whiskey in
glass bottles with such oak chips. It's not barrel aging, but it definitely
is wood aging!

I'd often wondered about doing that, even within a barrel. Something similar in concept to the Lincoln County Process but with an added time component. Great info, thanks Tim (and fun discussion too, takes me back to college p-Chem lectures!)

Re: barrel programs...can I buy and age my own bar

You can find some of the 4 liter bottles in duty free sometimes. I bought a 4 liter JB White 7-8 years ago in a duty free. Same with Johnnie Walker Black, they had a 4 liter at the Niagara Falls duty free just last month.

I was on a tour of Beam once and was watching them bottle some huge bottles for overseas somewhere, they were 3 or 4 liter bottles. Putting on the labels was like wallpapering I've never wanted a bottle of Beam white label so bad in my life.

Come to think of it, in 2001, at the Gala, they were pouring Four Roses out of the same size bottle